Device for removing sheets singly from a pile of sheets



Dec 118 ,11923.

R. LEUMANN DEVICE FOR REMOVING SHEETS SINGLY FROM A FILE OF SHEETS 3 Sheets-Sheet 1 Filed March 11,477,835 R. LEUMANN DEVICE FOR REMOVING SHEETS SINGLY FROM A PILE OF SHEETS Filed March 31. 1921 3 Sheets-Sheet 2 Dec. 18 11923.

I Dec. 118, 11923.

R. LEUMANN DEVICE FOR REMOVING SHEETS SINGLY FROM A FILE OF SHEETS Filed March 51. 1921 3 Sheets-Sheet 3 Patented @ec. l8, fi;.'.l'l

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TNT @FFHQIEO RD LE'UN, F CHAILLY-SUR-LAUSANN'E, SWITZERLAND.

DEVICE FOR REMOVING SHEETS SINGLY FROM A FILE OF SHEETS.

Application filed March 31, 1921.. Serial No. 457,433.

(GRANTED UNDER THE PROVISION$ OF T ACT OF MAR-OH 3, 1921, 41 STAT. L, 1313.)

To all whom it may concern.

Be it known that I, RICHARD LEUMANN, a citizen of the Republic of Switzerland, residing at Chailly-sur-Lausanne, Switzerland, have invented certain new and useful Improvements in a Device for Removing Sheets S-ingly from a File of Sheets (for which I have obtained a patent in Germany dated August 29, 1914, No. 292,966); and i to do hereb declare the following to be a clear, full, an exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use'the same, reference being had to the accompanyw ing drawings, and to letters or figures of re erence marked thereon, which form a part of this specification.

This invention relates to improvements in a device for removing sheets singly from a so pile of sheets. Devices of this type are known in which the removal is elfected by means of a pneumatic sucker device acting upon the lowermost of the sheets. The known devices present the disadvantage that $5 the sheets resist to being bent during the removal and that a comparatively great suction action isneeded.

The present invention has for its object to overcome this diiiiculty by positively caus- 39 ing the sheets to bend towards the sucker device in a downward direction. Thereby the resistance which occurs when sucking the single sheets at these points of curvature is decreased. In machines of this type it is seldom that the paper is absolutely flat, or if flat the sheet is buckled when initially seized by the sucker, and this buckling must be broken or overcome when the sheet is pulled down, by a transverse bend at the 41 edge of the supportfor the stack of paper.

According to my invention the overhanging front portion of the stack is given a slight bend or curve downward, so that no buckling will occur, or if it does occur will be in front of the line of transverse bend BJld. not increase the resistance to bend- .9 in the direction desired.

he force required to bend a sheet of paper across a buckled portion is many times greater than that re uired to make a transverse bend in a fiat s act, or that required to continue the bending of an already bent sheet. The pneumatic sucker device therefore acts upon the ends of sheets with which this initial bending resistance has already been overcome, whereby a reliable working of the device results.

One mode of carryingthe invention into effect is shown by way of example in the accompanying drawings, in which- Fig. 1 is a vertical longitudinal section;

Fig. 2 a plan view and Fig. 3 a cross-section of the device.

Fi 4 and 5 show parts of the device in dsu sequent different working positions, an

Fig. 6 is an elevation showing in a diagrammatic manner the drive of the parts of the device.

1 denotes a receptacle containing the pile of sheets, the receptacle is supported by a stand 2. The bottom 3 of this receptacle is bent in a downward direction to a shape which is desirable for the sheets to be curved to. At the front end of the bottom of the receptacle a roller 4c turnably mounted on an axle 5 is provided serving to decrease the friction, when removing the lowermost sheet. A stirrup shaped member or sucker device 6 is rotatably mounted on set screws 6 acting as fulcrums, the member 6 is provided with projecting parts 8 and 9. The part 9 is arranged as a sucker and provided with bores 10 leading to a pipe 11 which is connected by a flexible hose 12 to an airpump 44, (Fig. 6). The parts 8 serve to support the sheets. Another stirrupshaped organ 14; which may be hereinafter called the separator is turnably mounted in axles 13 and is provided with two tapered projections 15. The turning motion of the separator is derived from the driving shaft 29 by the interposition of a link 30 connected to one arm of a double-armed lever 31, adapted to swing about an axle 31' the other arm of which is provided with a roller 32 coacting with an eccentric 33 fixed to tong 23 is provided adapted to move up and down a vertical guide 37 and serving to gripthe end of the sheet removed by the sucker and to pull it out of the receptacle in a downward direction. The tong 23 is actuated by means of a link 38, connected to one arm of a bell crank lever 39 adapted to swing about a fixed fulcrum 40, the other arm of the bell crank lever 39 being provided with a roller 41 engaging with a cam groove 42 of a cam disc 43 mounted on the driving shaft 29. The air pum 44, 45, which is shown in Fig. 6, is of tl fe known type comprising a piston 44 fixed ,to the stand 2, a movable cylinder 45 and a spring 46 arranged inside the pump and tending to force the cylinder in a downward direction, for performing the suction stroke. A bell crank lever 47 is adapted to lift the cylinder, which lever is turnably mounted on a fixed fulcrum 48, and provided at its one arm with a roller 49 coacting with an eccentric 50 fitted on the driving shaft 29. The rear ends of the sheets are held by a sliding piece 24 adapted to be adjusted in the longitudinal direction of the'sheets by means of a spindle 25 provided with a thumb nut '26 so that the piled up sheets are forced to adapt ,the curved position at their front end. 27 denote supports fixed to the front plate of the receptacle 1 on which the sheets rest.

The operation of the above described device is as follows:

the sucker 9 is in its forward position in touch with the lowermost sheet curved towards the sucker and which is held by suction action. A rotation of the driving shaft 29 in the direction of the arrow permits of the bell-crank lever to turn in a clockwise direction, whereupon the spring 22 causes the sucker device to turn towards the rlght into the position shown in Fig. 4,

' the sucked on sheet taking part in that movement. Immediateiy thereafter roller 32 rides off the nose of cam 33 and permits spring 20 to turn the stirrup-shaped element 14 and taplered projections thereon into the posltion s 23 is caused to move upward by the rotation of the driving shaft through the inter osition of. cam disc 43, cam groove 42, ellcrank lever 39 and link 38; the tong grips own 1n Fig. 4. Then thetong the sheet'and pulls it out of the container in its downward movement. The sheets re maining in the container are supported by the fixed supports 27 and the parts 15 of the separator as shown in Fig. 4. The separator 14 is in its lowest position when the sucker 9 acts upon the lowermost sheet (Figs. 1. and 6). As soon as thesucker 9 has moved past the parts 15 of the separator the latter is moved into its highest position. Thereby if the sucker has from any reason partly removed also the next but lowermost sheet (Fig. 5) the latter is moved back towards the other sheets before it can be gripped by the tong. The relative arrangement of the eccentric 33 actuating the separator and of the cam groove 42 actuating the tong is such that the separator will first be moved into its highest position and then the tong performs its upward movement.

I claim:

1. In a sheet feeding device means to support a stack of sheets slightly inclined with their forward ends overhanging said means and downwardly flexed, means to force and hold the sheets in such position, a sucker device co-operating with the overhanging end of the lowermost downwardly bent sheet, and means to move said device to flex the lowermost sheet to a greater degree in the direction of initial flexure to thereby separate the front end of the lowermost sheet from the sheets above it, and means to seize and withdraw the lowermost sheet from the stack. 1

2. In a sheet feeding device, a receptacle having a bottom supporting a stack of sheets slightly inclined with their forward to flex said sheet-to a greater degree in the In the. posltion shown in Figs. 1 and 6 direction of its initial flexure and thereby flex the forward end of the sheet from.the

stack, and means to seize and withdraw said sheet from the stack;

3. A sheet feeding mechanism, having a receptacle adapted to hold a pile of sheets in a slightly inclined direction, a sucker device co-acting with the front ends of said sheets, and means to cause a pressure to the back of the pile of sheets held in said receptacle to urge them against the front wall of said receptacle and to effect thereby a flexing in the downward direction toward said sucker of the front ends of the sheets, whereby the resistance offered by said sheets to the action of said sucker device that causes a further flexing of said sheets in the same direction is reduced.

4. In a sheet feeding device, a receptacle having a downwardly curved bottom sup- 'lii sheet from the stack by flexing it in the porting a stack of sheets slightly inclined direction of initial flexure, and means to with their forward ends overhanging the seize and remove the so separated sheet. front edge of said bottom and against the In testimony that l claim the foregoing as front wall of said receptacle, means in said my invention, l[ have signed my name, receptacle to maintain the sheet stack in- RICHARD LEUMANN. clinecl to the rear, a sucker device to engage Witnesses: and separate the front end of the lowermost ALFRED MAEDER,

EDGAR ANDREY. 

